In a few weeks, the Treasury Department's czar of executive pay will have to answer this $100 million question: Should Andrew J. Hall get his bonus?

Mr. Hall, the 58-year-old head of Phibro, a small commodities trading firm in Westport, Conn., is due for a nine-figure payday, his cut of profits from a characteristically aggressive year of bets in the oil market.

There is little doubt that Mr. Hall is owed the money under his contract. The problem is that his contract is with Citigroup, which was saved with roughly $45 billion in taxpayer aid.